Method of making tires



F. G. NEAL ET AL METHOD 0F MAKING TIRES Filed Oct. i6., 1922 5 Sheets-Sheet 1 INVENTOR ATTORN May 5, 1925.

NEAL ET LAl.

May 5, 1925.

METHOD 0F MAKING TIRES Filed oct,

. 1922 3 Sheets-Sheet 2 lNVEN'gV/y ATTORNE May 5,5 1925. 1,536,723

F. G. NEAL ET AL METHOD 0F MAKING TIRES Filed Oct.. 16 1922 5 Sheets-Sheet :s

INVENTOR LEM/4; 4&0/

Bvywrvakm ATToRN'E/- FFAKJIN G. NMF, 0F SPFINGHE, AND DAVID Fi LUG-FFH', F GHICOPEE FALLS.-

MASSACHUSETTS, ASSGNORS T0 THF MSK RUBBER COMTE', 0E' CHICOPEE- FALLS, MASSACHUSETTS, .d COFIFF/ATFON UF MASSACHUSETTS.

rinrnon'oniarne ans.

application nierociober ie, ieee. semi nt. cuarta."

residing at Springfield, county of Hampden,

State of Massachusetts, and DAVID F. liocAiT, residing at Chicopee Falls,

' Hampden, State of assachusetts,have in vented certain new and usefulvlmprovements in Methods' of `Making Tires. ot` which we declare the following to be a` full', clear, and

exact description.

' rlhis invention relates to a method of tirev building. llt has peculiar advanta es in the f building of cord tires by the-end ess band or so-called pocket method. lts principal r advantages are in the speed and simplicity et the operations, in the character of stretch vgiven to the cord bands, in the waytlie bands are ositioned on the building'core, and in com ination of certainoperating steps. to

build even very large tires with convenience. |Fhe general object of the invention is to improve the method ot building tires. The general and specific objects will be bett/er understood from a detailed description ot applicationsfin use. y

'lbe invention is illustrated vand described in one ot the preferred forms in which it may be used.

the method according toene of its practical Fig. 1v illustrates a portion of a' four-ply 4 band orpocket with sections of the plies removed to show the laminated construction and arrangement of the cord layers.

Fig. 2 is a sectional view on line 2-2 ot i Fig. 3 of the band stretching apparatus with .the cord band in place betere the principal stretching operation.

Fig. 3 is a `front view of the stretching apparatus without the cord band on it.

Fig.` l is a View like Fig. 2 but with the` apparatus in expanded position and with the cord bandv in place alter the principal stretchingoperation.-

. Fig. 5 is a sectional view of a collapsible tire building core or lforni with the-'tourply band on it. and mounted' on atchuck, all conveniently supported in building position- Fig. o is a cross sectional View through the 'core with the beads applied at the sides-ot vthe band as the latter his conformed to the core.

Fig..7 is'a` view like Fig. b but with the edges of the `twoinside plies turned or tolded under and around -the beads; the ends of i each ply are arbitrarily represented by large dots to show their position. rlhis plan is also carried out in tbel otherigures.

Fig.V 8 illustrates a portion ot a two-ply` i I band or pocket with sections removed to show the construction 'and arrangement of .the layersl rig. 1o is a View like rig-abut with um edges of the two-ply band applied over and under the. beads.

. Fig. 11 is a view like Fig. 10 but with the covering rubber in position over the carcass. i

Fig. 12 isa perspective view 'toillustrate the position orcondition of the cord band ot tour or,` two plies after it has been vcontraction as indicated in Figs. 5 and-9.

'stretched on the apparatus fotFigs. 2, 3, and

Fig. 13 is aconventional'cross section ofv a tire nished as 11 and ready for',

vulcanization. Y

Fig. lll avview of the same tire after it is vulcanied in a niold and expandedto the mold by internal' expanding pressure.

, rlhe drawings are not'niade to an exact are built into sheet 'torni with layers of protecting rubber.

ln the, illustrated embodimentl of the invention the rubberized cord is laminated in dat and endless band form. rlhecords in one ply preferably. cross the cords ot an adjacent ply'and the cords are arranged at an acutetangle shown in this instance'as 30 to theedges oit' the band. Such a band consisting oi four plies is illustrated in Fig. l.

Iscale butitor the'purpose ot better illustratlill) llts'diarneteris approniinately that of the' I bead line or edge ot the finished tire. f'lhe number `ot cords per inch, measured'at right. 5 angles to the cord length, is that number deplied to the stretcher.

sired at the bead edge, and the angle of the `diameter will result in the number of cords per inch at the crown as desired. These are Controlling factors, as will be recognized by the tire builder, because a change of -angle will give avchange in cord number per inch from the bead line as a starting point to the. crown of the tire as an end point. lVide variations in tire structure, building operations, and strength, will result -from the chosen number'of cords per inch at the bead line, the angle of the cords from bead to bead and the character of stretch given ,to a band of this character.

The'. band of Fig. 1 is placed over the rolls of the stretcher shown in Fig. 2, with the arms 1 and 2 in collapsed position. The perimeter measurement around the four corners or rolls of the stretcher in collapsed position shown in Fig. 2 is substantially that I of the unstretched band or at least such that the band can be conveniently aprlhe .band preferably iits on the rolls with a snug fit when applied by hand 'to the position of Fig. 2. rlhe arms 1 are fixed to shaft 3 supported by the Stand 5, but arms 2 are pivoted for rotation' about the shaft.l lt is convenient to have an extension 4; as a handle on arms 2.

'A preferred form of apparatus or tool for stretching is claimed in co-pending applications Serial Nos. 597,260 l'and 693,937, filed October 2T, 1922, and February 19, 1924, respectively.

llVith the band of Fig. 1 placed on the stretcher in "collapsed position shown in Fig. 2, the operator conveniently grasps the handle al attached toone of the arms 2 and rotates these arms through a small arc which gives a preliminary stretch to the band. By swinging the' arms-2 back and forth the band will gradually stretch even though it consists of four'or more plies as a, b, c, and d, of regular cord fabric, without more power being applied than can be readily exerted by the ordinary tire builder with the leverage disclosed in the apparatus. By repeated movements of the arms 2 the band is quickly stretched to the position indicated in Fig. 4e when it is at its maximum stretch so far as this stretching apparatus is concerned. V/'hen the band has reached this positionl it is preferable for the operator to swing the arms 2 down and back, describing an arc of substantially 1800, which action will distribute the band around the four rolls shown and in this manner distribute the stretch to the band so that it will not be unduly stretched at any localized point or points. As the band is stretched, it moves and is preferably caused to move to a substantial amount over the rolls. rlhese rolls are mounted in bearings at the outer ends of arms 1 and arms 2, all as shown in the drawing.'

The advantage in giving this character of stretch 'to the band lies in the fact that as the band moves around the stretching apparatus or more specifically over the rolls, there are no permanent conta/ct portions on the band, between which 'portions the stretching force is exerted. Therefore the force exerted on the band 'suspended between shifting contact portions stretches all portions more evenly. -If it were notl for the shifting of the band on the stretcher,

lthe contact portions being restricted would cause uneven stretching. Since the rolls and band move one relatively to the other particularly when the operator, as described, stretches the band in' small increments to begin with, and then with a sweeping movement to cause alarge relative movement between the rolls and band, the stretch is substantially distributed ovei the entire circumference or perimeter of the band. AThe specific stretching operation is by way of example only as different apparatus will give the same result in a different way. The time" taken in this stretching operation is preferably very short--amatter of a few seconds. vF or purposes of the illustrated case it is well inside of one minute.

When *the band is thus stretched, vthe stretcher is collapsed to the position of Fig 2. All portions of the band are thus simultaneously released from the stretching force. The band immediately after stretching is removed from the stretcher, and without delay placed over the core 10 of Fig. 5. It will be understood that the band thus placed over the core of Fig. 5 may be applied to the core by hand within a few seconds. This is so because the stretcher has expanded 1 the lband from substantially the diameter of the finished tire at the bead to the diameter of the finished carcass at the crown, which substantially corresponds to the crown diameter of the core. `We prefer to stretch the band to a diameter a little less, rather than a little more, than the crown diameter. ln any event, it should be stretched so as to make the application to the core possible by hand. r1`he diameter of the'band is referred to as if the band were circular. The fact is, however, that the band is not circular until placed on the core.

The transfer of the band from the stretching apparatus to the core is particularly important. The important feature involved is in the method by which the band is stretched in a substantially uniform manner and then transferred and centralized on. the core before the -band has time enough to shrink to an extent sufficient to interferev with the hand operation desired. rllhe materia-l of the band as described is such that itwill contract onthe core andwill do so with a high .degree of. uniformity,par?

i ticularly vif not stretchedtoo'niuchl and if iA the time between stretching and' application to the core is not too long.

lhe rubberized cord band vdescrilfiedl is..-

- transfer from thestretcherto the core there is nothing positively holding the band in stretched condition, that y is to say thev stretching force is released.

It is cle/'ar therefore that the time element is' important.

lt isa fact that the band will, when released,`

start to contract vbut there istime, as we have found from .actual practice, to make the transfer even with thepba'nd free. .As

' the band is being centralized on the pref cause as he centers the band and core, thel erably rigidcore as in Fig. 5, it continues to cbntract as itstarted to do when first released .from the stretcher. y rlthe crown, however, cannot contract `whenl centered over the vcrown of the core. vThe operator can continue vhis work without waiting, be-

edges are contracting all the time. llVhen the operator is ready, the contracted-skirts of the `band are in posit-ion for the bead application. `We believe that' the handling steps from the stretcherv tothe core assist A i in avoiding any uneven or local strains 1n the band. By treating the band in fiat form (as to cross section) during the stretching operation, releasing it simultaneouslyI and completely, then holding itlto carcass crown diameter at the/lcenterA only, and finally leaving it alone tov contract as lit will, we believe special benefits areattained, pai ti'cularly in the uniform character ofthe stretch andlay 'of the cord. The simplicity ofthe` operations for tire building will be apparent. l i

'According to this invention as described,

` we have found that the operator can stretch even a heavy band in the way illustrate-d, releasethe band, apply it by 'hand without any substantial difficulty to the core of Fig.` 5, and centralize it. without 4'the use of any applying or stretching tools at the core. The band of fourplies appears to lend itself to the objects desired even better than a two A ply band.I lBy this method it ispossiblc to A build a cord tire with remarkable ease by what known as the single stretch system, which system involves a sufficient stretch of the plies from their original unstretched condition so ,that in their application-to the corerthe plies will shrink on the core and substantially conform to 'the core from the i crown diameter to the bead diameterv of the tire to be built.

When the band has been applied as indi-v cated in Fig; 5, which ligure illustrates the band after it has had time to contract about the core, the operator places the beads 'first on one and then 4on the other side -of the band, and by moving the bead or endless ring constituting the bead filler axially of the core, the cords of the band on each side readily move inwardly from the position indicated in Fig.` 5 to that indicated in Fig. 6. This operation the workman has no vdifficulty in performing, as the edges, of .the outertwo plies of the band may .indicate the' position fcrthe toe of the bead, or other 'bead positioningin'eansmay be used. lf

he places the toe ofthe bead at the edges of these plies and then works the bead inwardlyby hand againsttlie 4core and pro gressively around the core, he will apply the-band smoothly tothe core with a cross sectiona's indicated in Fig; 6, and this without any `stitching operationlwliatever.

The edge portions ofthe inner two plies a and as indicated in-lig. 1 as Well as Fig. G, Aarewider thanthe outer two plies c and d.' and therefore when conformed to and over the beady so that they overlap the other two plies as indicated in F ig. 7. This is called the bead tie-in. The particular character. of this tie-in. chosen for the purposes of illustration is not .the only one which a tire builder may choose to use', as this particular ifeature may beffvaried ac cording to the -tire builders -.,preference.

2,A 3, and 4l in the saine manner as the' four ply band, and the two-ply band then placedA upon the core'aiid thus superimposed upon the four-ply band already on tl'i'e'- core` so that it occupies the position gencrallyin- Vdicated in Fig.' 9. The operator may find'in the application of this second band thatgthe 1'120 use of a liner placed around the four-'ply band and pulled out: after the applicationhf the twofply band will be convenient, but such use is not necessary, as the two-pli,7 band can -be centered on tlieco're as iiidi'f catedin Fig; 9 without any other assistance jtlie core-.extend inwardly Y, and below the bead. 'The operator folds these edges under 'lllhe drawings show one practical method bf applying the beads at the open edges of i Y the carcass.

.After the four-ply band has been. applied to the core as described, vthe two=ply` band of. Fig. 8 is stretched ontlie apparatusof Figs] than the operators hand work. Due to thel fact that` the core indicated-has a reverse curve at the regions immediately adjacent the bead line, and due to the fact thatfthe '13 piles in their application to the core under this method are not stitched down ty the core but are only caused to contract to conform to the core, thepedges of the carcassadjacent the bead line of the core do not tit tightly, as will. be apparent from the illustrations and Figs. 6, 7, 9, 10, and 11. fact is an advantage, as will be pointed out later. The width of Athe last two-ply band and each ply thereof is illustrated in Fig.' 9. With the bandin this position, the operator takes a hand roller., preferably one with a concave working tace, and rolls the two-ply band down against the four-ply band and then folds the edges under the bead, The edge portions of ply e are folded inside'the bead edges when the side walls and chaling strip are applied.v All this work can be done vby hand without assistance of any iipower, as the parts are all placed in condicludes the insertion of an air bag in the carcass, the placing of the, carcass and air Cil tion for easy application by the stretching operations.

The carcass finished in the manner indicated in Fig. 10 is then covered by the usual finishing operations including-the application of rubber tread, breaker, sidewalls, and

chaing strip, all indicated in Fig. 11. At the same time that the ehafing strip is folded inside the tire, the edge portions ot' ply c are likewise folded as indicated in Fig. 1l. This work is rendered much easier due to the tact that the carcass docs not fit the core tightly at the bead edges.

As indicated in Fig. 5, the core upon which the tire is huilt is preferably mounted on a chuck operable (for example like the core oit De Mattia Paten-t 1.328,1Gl) to pull the sections of the core out ott-he interior of the carcass so that the carcass may be readily removed from the core. The iinished carcass then has the general cross section outline of Fig. 13 and is ready for vulcanizing.

rlhe vulcanizi'ng step preferred and important to this particularmethod is that of internal expansion against the interior ot a closed mold. rthis way of curing cord tires is well understood,v and ordinarily inbag in the inside of a mold which is then closed and heated while the air bag is kept under pressure during vulcanization. The carcass, due to the internal pressure ot the air bag, is expanded from the outline of Fig. 13 to the outline ot Fig. l-t as illustrated, during which time the non-skid design may be placed by the molding surface on the covering rubber or tread portions.

This increasein size in the vulcanizing step from'the carcass as built to the carcass as cured, causes the parts above the bead to be stretched under and by fluid pressure and all parts to -be all pressed into a homogene' ous unit dueto the pressure of the air bag towards the mold with the tire between. rlhe 'raie causes an accurate movement of the carcass materials to the desired tire shape determined by the mold. The carcass materials are assembled on thel core in the building operations by hand Without' the necessary use of any power tools to compact the materials of the carcass in any manner analogous to the compaeting of said materials in the stitching 4operations by machinery. This .so-called loose assembly' is believed to be of considerable advantage because of the freedom-from distorting strains When the carcass is forced under iuid pressure from the size represented by Fig. 13 to that size represented by F ig. 14. The fiuid pressure causing this increase yin size is more than suiiicient to ,compact the parts of the assembled carcass materials and is applied when these materials are forced to their ultimate positions in the tire.

Many variations may be made from. the details of the method herein described and illustrated as one preferred form; l For example, a skilled. tire builder or designer will make the number, arrangement, and type ot his strain resisting cords what he wants. He will vary the bead tie-in7 at the band edges to contorni to his own ideas. ,life may choose to stretch and apply all of the carcass bands or laminations at one time instead ot splitting the Operation between the plies under the bead and the plies over the bead as now shown in the illustration. The tread and sidewalls may be stretched and applied simultaneously or separately with respect to the band ot carcass cords. Oi course a clincher type bead filler may be used instead otA the inextensible or straight side type shown. These are only somel ot the variations which may be made within the spirit and scope of the claims as they particularly point out the invention.

Having thus described our invention, we

claim:

1. ln a method of tire building, the steps of stretching an endless band of carcass material in substantially flat form on a stretcher, completely releasing the band for a short interval of self-adjustment, and then applying the loose band to atire shaping former.

2. In a method ot tire building, the steps of stretching an endless band of carcass laminations in substantially Hat form on a stretcher from the bead to the crown circumference of' an uncured carcass, completely releasing the band for a short interval ot' self-adjustment, and then applyingthe loose band to a tire shaping former before it has contracted a substantial amount.

3. ln a method of tire building, the steps of stretching an endless band in substantially fiat cross section by successively applying oppositely acting forces at different porweaves tions of the band as it is being expanded,

Y completely're'leasing the band forself-adf justment to its stretched condition, vandthen centering `it on a tire shapingformerbefore it has had timeto contract a substantial amount. 4

. 4f. Ina method of tire building,t he 'stepsV of stretching an' endlessband 'of carcass material .in substantially flat cross sectional shape, completely! releasing the band from. -the stretching force kfor a short interval of self-adjustment and then Aapplying the band to a tire building former for. shaping by the contraction of the'stretchedAbandon the former. y

5. In a method of ytire building, the steps of uniformly stretching an endless substanthen applying Vthe loose band While'still in the time interval between the release of the band and its application to the former being less than that required 'for the band tocontract substantially from its stretched condition but sufficient to permit' it -toadjust itself. r A

6. In a method` of-,tirebu'ildinig7 the steps of stretching an vendlessband of carcass ma-l terial 'in substantially latformby succes sively applying oppositely acting-forces at different portions of the band as itis being expanded, and theniapplying said stretched band to a tire shapingformer after it has been released from said forces fora short period of readjustment.A

7 In amethod -vftire building, the steps. of circumferentially stretching an, endless -band of carcass material along both edges and the portions therebetween on a stretcher,

'releasing the band from the stretcher, permitting the bandv to readjust itself While loose, and then centering the Aband over a tire shaping .former before it has had time to contract asubstantial amount below the size of said tire shaping former.

` 8. In a method of tirebuilding, the steps of stretching an endless band on a stretcher until `it has a given diameter,- completely releasing the band from the stretcher' for a period of readjustment While loose and in substantially flat form, and thereafter transferring and applying it to a tire shaping former of substantially the same diameter before the band has shrunk in its loose condition a substantial amount below said diameter.

9. The method of -building tires which consists in building the carcass material in multiply substantially flat bands of al di-` ameter approximately equal to the 'bead diameter lof the tire, stretching vsaid bands v'vhile in fiat cross sectional form to a'diameter atleast equal to thecrown diameter of the tire, releasing said bands after stretching so they are free to contract while in vloose and unrestrainedcondition, successively .applying said bands to -a tire/shape' ing former beforethey have had time to contract a substantial amount, less than the sizeof said former; building bead portions at the side" edges of the bands when said edges are contracted to bead diameter,.co1n pleting the tire laminat-ions by adding the covering rubber, and finallyvvulcanizing the tires in molds under iinternal expanding pressure'acting toincrease the size of the finished tires.l v

10. In a method of tire of stretching all .portions of an endless band of carcass material ona'stretcher, simul taneously releasing all portions of the band from the stretching force, leaving it loose and in substantially flat cross sectional form while it readjusts itself and thereafter ap, plying the band over a tire shaping, former substantiallyl less than the size' of said former; f'

1l. In a method of tire building, the steps ofstretching all portions of an en dless band arranged at angles to the edges of the band and to each other on a stretcher, simultaneously releasing all portions ofthe band from the stretching force for a short vperiod of building, the steps l before it has hadtime toshrink to a size 1 a of four ormore plies'of rubberized cord readjustment of' forces inthe band While l loose' and in substantially flat cross sectional form, applying the band over a tire shaping former While still in its stretched conditionand in the act of shrinking, applying beads to the edge portions of the band after such portions have contracted from their stretched condition'and Without otherwise disturbing such edge portions, completing the tire structure in its raw state and finally i vulcanizing the tire structure under internal fluid pressureacting to stretch alll portions of'the tire above the bead edges.

12.` In a method of tire building, the steps ofstretching an endless band of carcass ma terial in substantially flat form on a stretcher, simultaneously releasing all`portions of the band from'` the stretcher, leaving said band loose for a short'period of unrestrained readj-ustrnent, and subsequently centering the' band overal tireshaping former While Ithe band' is still inthe act of shrinking from its stretched condition.

' 13. In a method of cord tire building, the steps of successively and uniformly stretching all portions ofelastic bands of carcass material to increase the size of the bands substantially from the bead circumference bands for a short period of readjustment,

and successively applying such bands to a" tire building former by centering thereon 'while s till'in stretched condition, then permitting said bands to 'shrink to approximately tire form, building the beads in the side edges of said bands while the said edges are substantially inthe condition brought `about by their shrinking action, whereby the carcass of the tire is built and formed substantially unrestrained except by the tire building former over which the carcass material is caused to shrink and the mere placing of the beads inthe side edges, applying the covering rubber 'to such carcass, an iinally finishing the tire by vulcanizing it under internal -pressure acting to uniformly stretch the tire above the bead edges.

14. In a method of tire building, the steps of stretching annular. careass material in substantially lat cross section for application to a tire shaping former, centering said material on the former in stretchedcondition and conforming the material to a part of the former by the progressive Ishrinking operations of the side portions of said ma-A terial and leaving the edge portions loose,

' incorporating bead members at the said edge portions leaving the edge portions still loose, completing the application of the tire material on. the carcass, and bringing the raw tire thus built to its ultimate form for service by internal pressure in a closed vulcanizing mold 'of larger size than the tire as laid up on the former.

l5.A In a method of cord tire building, the steps of longitudinally stretching all portions of an endless band of multi-ply rubberized cord carcass material on a stretcher,

releasing the band for an interval of seit adjustment while the band is loose and in substantially tiat cross sectional form, and then applying the loose band to a tire shap-I ing Jformer before the effect ot the stretching forces in the band has been dissipated.

1G. ln a method of cord tire building, the steps of stretching'all portions ot' a flat ring of elastic carcass material, then permitting it to shrink while loose and in substantially flat cross sectional form, and tinallv applying the loose band to a tire shaping former before the band has completed its shrinking action. f

17. ln a methodof cord tire building on a tire shaping former the steps which gonsist in stretchingl an endless tlat band ot carcass material circumferentiallly in all its portions to increase its size trom bead to crown circumference of the said former, in freeing the band from all external restraining means after it has been stretched and before it is applied to the said former, and thereafter centering `and applying it to` said former while loose and still in shrinking condition due to the stretching step, whereby thesaid bandmay be conveniently applied to said former under uniform tension conditions.

FRANKLIN G. NEAL. DAVID F. LOGAN. 

